From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <07cb01c3aae2$13f59be0$b9844051@insultant.net> From: "boyd, rounin" To: <9fans@cse.psu.edu> References: Subject: Re: [9fans] v8 shell MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Date: Fri, 14 Nov 2003 20:04:06 +0100 Topicbox-Message-UUID: 89a72c1e-eacc-11e9-9e20-41e7f4b1d025 > not to mention: > > tar c . | tee >{wc -c} | @{cd somewhere; tar x} > > are a constant joy. yes, but you needed /dev/fd (at the time) and very few systems did. norman wilson worked out that you could get at the newly allocated descriptor from some leftover in the u-area [index into u.u_ofile iirc] and from knowing that you could write /dev/fd as a driver, which meant no mods to the kernel. i wrote one for SCO lunix and then stuck it into ultrix and used it with byron's rc. of course, the ultrix development group wanted nothing to do with it, but it got released as a 'paper', back in '91 or so. the driver was a page of code, most of that taken up by a large copy-thing comment and a swath of #include's